Assembly for an aircraft propulsion assembly for separable coupling of two shaft by means of a coupling

Abstract

A separable coupling assembly (2) for an aircraft propulsion assembly (1), comprising: a first shaft (4) and a second shaft (6); a coupling sleeve (8) movable between a coupling position and a discoupling position of the shaft; a fluid chamber defined between the coupling sleeve and the shaft; a tube (10) extending into the bore of the coupling sleeve; and means (12) for selectively supplying a fluid (F) through the tube (10) to the first selected chamber (39, 52, 62) and the second selected chamber (64). When the coupling sleeve is in the coupled position, the pressure of the fluid in the first selected chamber applies a first axial force (F1) to the coupling sleeve that maintains the coupling. The pressure of the fluid (F) in the second selected chamber exerts a second axial force on the coupling sleeve that brings the sleeve into the discoupled position.

Description

Technical Field

[0001] The present invention relates to the field of aircraft propulsion assemblies, and more particularly to assemblies enabling a detachable coupling of two shafts, such as a first shaft mechanically coupled to an electric motor rotor and a second shaft mechanically coupled to a turbine rotor or a receiver, such as a propeller or a fan.

[0002] Such an assembly is particularly intended to enable efficient torque transmission between the turbine and the electric machine while being able to decouple the turbine and the electric machine in the event of a fault, or to prevent failure of the electric machine or equipment, components or systems related thereto, without requiring a complete shutdown of the turbine.

[0003] An aircraft's main propulsion engines typically drive non-propulsive generators at moderate speeds, typically around a few thousand revolutions per minute. These motors are sometimes susceptible to failure, particularly mechanical failures, which have a relatively high prevalence compared to the required reliability of the main engines. One way to continue using the propulsion engines is to mechanically disconnect the motors from the turbines.

[0004] As hybrid thermal / electric propulsion systems develop, it is desirable to develop a mechanical decoupling system that is reliable, lightweight, inexpensive, and easily integrated, and that also accommodates the unique characteristics of such systems.

[0005] In fact, in a propulsion assembly comprising a turbogenerator intended to generate electrical energy for propulsion, the electric motor has a power of the order of magnitude comparable to that of the turbine (this, however, depends on the number of electric motors driven by the turbine), while the non-propulsion electric motors of conventional propulsion assemblies are relatively "small" compared to the thermal motors.

[0006] Furthermore, the mechanical power received by the motor within such a propulsion assembly is much greater than the mechanical power received by the non-propulsion motor of a conventional propulsion assembly.

[0007] Moreover, the mass of such a machine is not negligible compared to the mass of the entire propulsion system, which generates a strong interest in optimizing this mass by using high-speed electric machines (on the order of tens of thousands of revolutions per minute) and / or by using permanent magnet machines (also called “PMG” according to the English term “Permanent Magnet Generators”) which have a high power-to-mass density but whose short-circuit conditions cannot be handled simply by de-energizing the rotor.

[0008] Furthermore, detachable coupling assemblies also find application in "parallel" hybrid propulsion assemblies, in which power can be selectively supplied to a receiver, such as a propeller, by a thermoelectric generator and / or an electric motor. When it is desirable to use a reversible electric motor, in particular to be able to perform functions such as recharging a power battery, it is desirable, or even necessary, to also have a detachable coupling mechanism between the electric motor-generator and the receiver. Background Art

[0009] There is a wide range of known separable coupling devices between two shafts. These devices essentially include:

[0010] a ramp device in which an actuator acts radially on a ramp fixed to one of the shafts in order to move this shaft axially, thereby decoupling this shaft from the other shaft;

[0011] - screw devices operating according to a similar principle to ramp devices, with the ramp being replaced by a thread and the actuator being shaped to act on the thread and to cause an axial displacement of the shaft in the manner of a screw-nut effect;

[0012] - ball devices, in which the connection between the shafts is achieved by means of a ball that can be separated from its housing to effect decoupling;

[0013] - Flywheel equipment, which can be separated on command;

[0014] - devices with an actuated frangible segment, wherein the breaking of the segment is caused by contact with a friction member controlled for this purpose;

[0015] - a device having a frangible section, the frangible section being made frangible by heat fusing; and

[0016] - Axial piston machines, in which a piston is displaced axially in order to decouple one of the shafts from the other.

[0017] The implementation of ramp and screw devices has the risk of jerking, which can limit the ability of ramp and screw devices to operate at high speeds, and these devices generally have the risk of premature wear. In addition, the radial dimensions of the actuators of such devices are sometimes unacceptable.

[0018] Ball equipment is usually characterized by irreversible operation, prohibiting any possibility of reconditioning.

[0019] Fragile devices are destructive and may damage nearby components. Additionally, these devices cannot be tested.

[0020] Document EP3746669A1 provides an example of a device of the latter type (i.e., with an axial piston), in which an annular hydraulic actuator is arranged around a coupling sleeve itself, which is inserted axially between the two shafts to be connected. The hydraulic actuator is configured to move the coupling sleeve axially under the action of fluid pressure in order to decouple the coupling sleeve from one of the shafts.

[0021] However, due to the relatively large number of moving parts involved in the operation of such equipment, such equipment has proven to be cumbersome and expensive.

[0022] Therefore, there is a need for an assembly that enables a separable connection, with limited mass and size.

[0023] There is also a need for an assembly that allows for a detachable coupling that is as suitable as possible for coupling shafts intended to transmit propulsion power (typically having to transmit power levels in the order of several hundred kilowatts) and / or shafts rotating at high speeds (typically in the order of tens of thousands of revolutions per minute), and / or for transmitting power in both directions of rotation. The latter characteristic is particularly relevant in the case of electric motors generating propulsion power, which also serve as starters for turbines.

[0024] Finally, a need exists for a separable coupling assembly having a reversible mode of operation so that the separable coupling assembly can be rearmed. Summary of the Invention

[0025] The present invention aims to at least partially remedy these needs.

[0026] To this end, the present invention proposes a detachable connection assembly for an aircraft propulsion assembly, the detachable connection assembly comprising:

[0027] - a first shaft and a second shaft, the first shaft and the second shaft being mounted to rotate relative to the stator along an axis;

[0028] a coupling sleeve comprising a first coupling device arranged on a first axial side and a second coupling device arranged on a second axial side, the coupling sleeve being axially movable between a first position and a second position, in which the first coupling device and the second coupling device are coupled to the first shaft and the second shaft, respectively, and in which the coupling sleeve is displaced relative to the first position towards the second axial side so that the first coupling device is decoupled from the first shaft;

[0029] - a fluid chamber defined between the coupling sleeve and at least one of the first and second shafts;

[0030] a tube fixed to the stator and extending into the bore of the coupling sleeve; and

[0031] - a fluid supply device configured to selectively supply fluid to a first selected chamber from the fluid chambers and a second selected chamber from the fluid chambers through the tube;

[0032] The fluid chamber is configured such that:

[0033] - the pressure of the fluid in the first selected chamber exerts a first axial force on the coupling sleeve directed towards the first axial side, at least when the coupling sleeve is in the first position; and

[0034] The pressure of the fluid in the second selected chamber exerts a second axial force on the coupling sleeve directed towards the second axial side, in order to bring the coupling sleeve into the second position.

[0035] The present invention therefore proposes a separable coupling assembly of limited size and mass and suitable for the applications mentioned above.

[0036] In a preferred embodiment of the present invention, the fluid supply device comprises a first supply channel in fluid communication with a first selected chamber, a second supply channel in fluid communication with a second selected chamber, and a device for selectively supplying the fluid to the first and second supply channels.

[0037] In a preferred embodiment of the present invention, the first selected chamber comprises a lubrication chamber of the first coupling device and a lubrication chamber of the second coupling device, and at least one first actuation chamber, the at least one first actuation chamber being configured such that, at least when the coupling sleeve is in the first position, the first axial force is at least primarily generated by the pressure of the fluid in the first actuation chamber.

[0038] Preferably, the second selection of chambers comprises at least one second actuation chamber and excludes said lubrication chamber of the first coupling device and said lubrication chamber of the second coupling device.

[0039] Alternatively, the first selection of chambers comprises only the lubrication chamber(s) of the first coupling device and the lubrication chamber(s) of the second coupling device, and the second selection of chambers comprises only the lubrication chamber(s) of the first coupling device.

[0040] In a preferred embodiment of the invention, the first coupling means and / or the second coupling means form a spline or define a dog-clutch connection.

[0041] The present invention also relates to an aircraft propulsion assembly comprising a receiver, an electric motor, a turbine, and an assembly of the above type, wherein a first shaft of the assembly is mechanically engaged with a rotor of the electric motor and a second shaft of the assembly is mechanically engaged with a rotor of the turbine, and wherein at least one of the electric motor and the turbine is configured to transmit propulsion power to the receiver.

[0042] In a preferred embodiment of the invention, the propulsion assembly includes an idler pinion mechanically engaged with the second shaft and the rotor of the turbine.

[0043] Preferably, at least a first selected chamber is in fluid communication with the interface to mesh the second shaft with the idler pinion.

[0044] Preferably, the second selected chamber is also in fluid communication with the interface.

[0045] In a preferred embodiment of the invention, the electric machine is configured to receive propulsion power from the first shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The invention will be better understood and further details, advantages and features of the invention will emerge on reading the following description given by way of non-limiting example and with reference to the accompanying drawings, in which:

[0047] [ Figure 1 ] is a schematic axial cross-sectional view of an aircraft propulsion assembly including a motor, a turbine, and a separable coupling assembly;

[0048] [ Figure 2 ] is a schematic axial cross-sectional view of a separable coupling assembly according to a first embodiment of the present invention, which may be Figure 1 A portion of a propulsion assembly shown in a coupled configuration;

[0049] [ Figure 3 ] is similar to Figure 2 , wherein the assembly is shown at the beginning of the decoupling phase;

[0050] [ Figure 4 ] is similar to Figure 2 , wherein the assembly is shown in a decoupled configuration at the end of a decoupling phase;

[0051] [ Figure 5 ] is similar to Figure 2 , showing a detachable coupling assembly according to a second embodiment of the present invention, the detachable coupling assembly can also be formed Figure 1 part of a propulsion assembly;

[0052] [ Figure 6 ] is similar to Figure 5 , wherein the assembly is shown at the beginning of the decoupling phase;

[0053] [ Figure 7 ] is similar to Figure 5 , wherein the assembly is shown in a decoupled configuration at the end of a decoupling phase;

[0054] [ Figure 8 ] is similar to Figure 2 , showing a variant with a preloaded spring.

[0055] Throughout the drawings, the same reference numbers may identify the same or similar elements. DETAILED DESCRIPTION

[0056] Figure 1 An aircraft propulsion assembly 1 is shown very schematically and comprises an assembly 2 for realizing a detachable coupling, the assembly 2 generally comprising a first shaft 4, a second shaft 6, a coupling sleeve 8, and a pipe 10 associated with a fluid supply device 12. Figures 2 to 4 The assembly 2 , visible in more detail in FIG, is intended to transmit rotational movement between the shafts 4 and 6 .

[0057] The first shaft 4 is usually mounted on the first side C1 of the assembly by means of one or more guide bearings 18 (one of which is located at Figures 2 to 4 The second shaft 6 is mounted for rotation relative to the stator 16 along the axis 14 (visible in FIG. 1 ). The second shaft 6 is typically mounted for rotation relative to the stator 16 along the axis 14 at the second side C2 of the assembly by means of one or more (e.g., two) guide bearings 20A, 20B. The tube 10 is preferably fixed to the stator 16 and extends from one end of the coupling sleeve 8 (e.g., the end of the coupling sleeve 8 located at the second side C2) into a bore defined in the coupling sleeve 8.

[0058] According to the terminology used in this specification, the axis 14 defines an “axial” direction.

[0059] In the embodiment, the first shaft 4 is thus mechanically coupled to the motor rotor and the second shaft 6 is mechanically coupled to the turbine rotor. By "mechanically coupled" elements it is understood that these elements are rotationally fixed or form a gear or gear train by being mechanically connected by means of one or more pinions.

[0060] In the example shown, the first shaft 4 is thus fixed to the rotor 22 of the electric motor 24 ( Figure 1 ), and the second shaft 6 forms a pinion because the second shaft 6 has a spline 25, and the second shaft 6 is connected to the idler pinion 26 (at Figure 1 is fully visible in Figures 2 to 4 The idler pinion 26 is also engaged with the rotor 28 of the turbine 29 of the turbine 30 (partially visible in FIG. Figure 1 ). Thus, the idler pinion 26 ensures the transmission of the rotational movement between the second shaft 6 and the rotor 28 of the turbine 29 .

[0061] Furthermore, the propulsion assembly 1 comprises a receiver 32, such as a propeller or a fan, the drive of which relies on the energy supplied by at least one of the electric motor 24 and the turbine 30 (if applicable, the energy supplied by the rotor 28 of the turbine 29), in order to ensure the propulsion of the aircraft. The energy supplied by the electric motor 24 can be electrical or mechanical, depending on the type of architecture of the propulsion assembly and on the role played by the electric motor within the propulsion assembly.

[0062] The assembly 2 is notably intended to form part of a mechanical propulsion transmission system within a hybrid propulsion assembly of an aircraft.

[0063] The propulsion assembly 1 is, for example, a series hybrid propulsion assembly in which a receiver 32 is mechanically coupled to an electric motor 33, which is supplied with electrical energy by a distribution unit 34, which itself is supplied with electrical energy by (on the one hand) a power battery 35 and (on the other hand) an electric motor 24 connected in parallel. The electric motor 24 is thus configured to operate as a generator of propulsion electrical energy by converting the mechanical energy received from the turbine 30 and supplying the resulting electrical energy to the distribution unit 34. The distribution unit 34 typically comprises a DC / AC conversion device and an AC / DC conversion device. The distribution unit 34 thus also makes it possible to recharge the power battery 35 with excess electrical power during certain operating phases. In this case, alternatively or additionally, a detachable coupling assembly similar to the assembly 2 described in detail below can ensure the coupling between the shaft of the receiver 32 and the rotor of the electric motor 33.

[0064] Alternatively, propulsion assembly 1 may be a parallel hybrid propulsion assembly, i.e., comprising a mechanical transmission system and parallel turbines. The mechanical transmission system, for example, is of the type including a gear train reducer configured to couple the electric motor to the receiver so as to selectively operate as a motor or a generator. In this case, when the electric motor operates as a motor, it is supplied with electrical energy from a power battery, and when the electric motor operates as a generator driven by the turbine via the mechanical transmission system, the electric motor recharges the battery. In such an application, the separable coupling assembly, for example, mechanically engages the first and second shafts with the mechanical transmission system and the rotor of the electric motor, respectively.

[0065] In order to be able to transmit the rotational movement between the shafts 4 and 6, the assembly 2 comprises a coupling sleeve 8 arranged coaxially with the shafts 4 and 6 and movable along the axis 14 between a first position and a second position, the first position also being called the coupling position and being in the Figure 2 As can be seen in the figure, in the first position, the sleeve 8 effectively ensures the coupling between the two shafts 4 and 6, and the second position is also called the separation position and is Figure 4 As can be seen in FIG, in the second position, the sleeve 8 does not ensure this coupling and therefore allows the shafts 4 and 6 to rotate relative to each other.

[0066] The movement of the coupling sleeve 8 from the coupled position to the decoupled position is achieved by selectively supplying a fluid F (indicated by dots in the figure) supplied by a fluid supply device 12 via a pipe 10 to a fluid chamber defined between the sleeve 8 and at least one of the shafts 4 and 6, so that the pressure of the fluid F in the relevant fluid chamber exerts an axial force on the sleeve 8, thereby moving the sleeve 8 axially. The pressure of the fluid F is caused, for example, by the centrifugal effect of the fluid in contact with the rotating components defining the relevant chamber. In this case, the higher the rotational speed of these components, the greater the axial force.

[0067] The coupled and decoupled positions are advantageously defined by means of a stop 36 (eg a flange), in the first case ( Figure 2 ), the stopper 36 bears against one end of the first shaft 4, and in the second case ( Figure 4 ) under the stopper 36, which bears against one end of the second shaft 6.

[0068] More specifically, the invention provides for selectively supplying a first selected chamber and a second selected chamber so that, in the first case, the pressure of the fluid F in the chamber exerts on the sleeve 8 a first axial force F1 directed towards the first axial side C1 ( Figure 2 ), thereby maintaining the sleeve 8 in the coupled position, and causing, in a second instance, the pressure of the fluid F in the chamber to exert on the sleeve 8 a second axial force F2 directed towards the second axial side C2, thereby bringing the sleeve 8 into the decoupled position. Furthermore, in the preferred embodiment shown, the aforementioned fluid F is also used to lubricate the means for coupling the sleeve 8 to the shafts 4 and 6, as will become more apparent below. In this case, the fluid F chosen is therefore a lubricant, for example a lubricating oil.

[0069] In the example shown, the coupling sleeve 8 has a first portion 8A situated on the first side C1 and extending into the bore 4A of the first shaft 4 , and a second portion 8B situated on the second side C2 and extending into the bore 6A of the second shaft 6 , the shafts 4 and 6 being in fact hollow shafts.

[0070] The first portion 8A of the sleeve 8 comprises first coupling means 37 which, in the coupling position ( Figure 2 ), the sleeve 8 is coupled to the first shaft 4 via a first coupling device 37.

[0071] In the example shown, the first coupling means 37 are splines extending radially outwards from the outer surface of the first portion 8A of the sleeve 8 and cooperating by mutual engagement with splines 38 extending radially inwards from the inner surface of the first shaft 4 defining its bore.

[0072] The first shaft 4 and the first portion 8A of the sleeve 8 are configured to define a first lubrication chamber 39 intended to be lubricated in the coupled position ( Figure 2 ), the first coupling device 37 can be lubricated.

[0073] To this end, the first shaft 4 comprises, for example, a structure 40 (e.g., a shoulder) that projects inwardly from the inner surface of the shaft 4, extends to a short distance from the outer surface of the first portion 8A, and is located outside the first coupling device 37, toward the first side C1. Furthermore, the first portion 8A comprises, for example, a structure 42 (e.g., a flange) that projects outwardly from the outer surface of the first portion 8A, extends to a short distance from the inner surface of the shaft 4, and is located outside the first coupling device 37, toward the second side C2. Thus, the structures 40 and 42 delimit axially between them the first lubrication chamber 39 of the first coupling device 37.

[0074] For example, the first shaft 4 comprises one or more first drain holes 44 connecting the first lubrication chamber 39 with the exterior of the shaft.

[0075] In the example shown, the sealing of the chamber 39 is reinforced by means of a compressible annular seal 45 housed in a groove 46 arranged outside the structure 42 towards the second side C2 and formed in one of the first shaft 4 and the first portion 8A of the sleeve 8, so that the seal 45 exerts pressure against the other of these two elements.

[0076] The pressure of the fluid F in the chamber 39 causes an axial force E1 to be exerted on the sleeve 8 .

[0077] The second portion 8B of the sleeve 8 comprises a second coupling means 48 which, in the coupling position ( Figure 2 ), the sleeve 8 is coupled to the second shaft 6 via a second coupling device 48 .

[0078] In the example shown, the second coupling means 48 are splines extending radially outwards from the outer surface of the second portion 8B of the sleeve 8 and cooperating by mutual engagement with splines 50 extending radially inwards from the inner surface of the second shaft 6 delimiting its bore.

[0079] The second shaft 6 and the second portion 8B of the sleeve 8 are configured to define a second lubrication chamber 52 intended to ensure that in the coupled position ( Figure 2 ) Lubricate the second coupling device 48.

[0080] To this end, the second shaft 6 includes, for example, a structure 54 (e.g., a flange) that projects inwardly from the inner surface of the shaft 6, extends to a short distance from the outer surface of the second portion 8B, and is located outside the second coupling device 48 toward the second side C2. Furthermore, the second portion 8B includes, for example, a structure 56 (e.g., a portion with a gradually expanding cross-section) that projects outwardly from the outer surface of the second portion 8B, extends to a short distance from the inner surface of the shaft 6, and is located outside the second coupling device 48 toward the first side C1. Thus, the structures 54 and 56 axially delimit the second lubrication chamber 52 between them.

[0081] For example, as will appear more clearly below, the second shaft 6 comprises one or more second drain holes 58 connecting the second lubrication chamber 52 to the exterior of the shaft.

[0082] In the example shown, the sealing of the chamber 52 is reinforced by means of a compressible annular seal 59 housed in a groove 60 arranged outside the structure 56 towards the first side C1 and formed in the second portion 8B of the second shaft 6 and / or sleeve 8 .

[0083] The pressure of the fluid F in the chamber 52 causes an axial force E2 to be exerted on the sleeve 8 .

[0084] In addition, Figures 2 to 4 In the embodiment of , the coupling sleeve 8 and the second shaft 6 delimit between them a first actuation chamber 62 , for example of annular shape, and a second actuation chamber 64 , for example also of annular shape.

[0085] The first actuation chamber 62 is configured such that the pressure of the fluid F within the first actuation chamber 62 causes an axial force E3 directed towards the first axial side C1 to be exerted on the coupling sleeve 8 , at least when the coupling sleeve is in the first position.

[0086] In contrast, the second actuation chamber 64 is configured such that the pressure of the fluid F in this chamber causes an axial force E4 to be exerted on the coupling sleeve 8 , which is directed towards the second axial side C2 .

[0087] The lubrication chambers 39 and 52 are configured such that the axial forces E1 and E2, respectively, exerted on the sleeve 8 due to the fluid pressure within these lubrication chambers 39 and 52, substantially cancel each other out. Alternatively, these chambers may be configured such that the axial forces E1 and E2 generate a resultant force that is in the same direction as the axial force E3 (i.e., directed toward the first side C1), or a resultant force that is in the opposite direction to the axial force E3 but has a smaller magnitude than the axial force E3. Thus, in all cases, it is ensured that the first axial force F1 generated by all the axial forces E1, E2, and E3 is directed toward the first side C1.

[0088] A person skilled in the art will understand that the means for achieving this result are based on the choice of the orientation of the surfaces delimiting the lubrication chambers 39 and 52 and the actuation chambers 62 and 64, on the choice of the respective inner and outer diameters of the chambers, and on the choice of the surface fixed to the sleeve 8 or to one of the shafts 4 and 6 arranged on the first side C1 or the second side C2, respectively.

[0089] Thus, in the example shown, the surfaces that delimit the actuation chambers 62 and 64 internally and externally are cylindrical in shape and therefore do not contribute to the axial forces E3 and E4. Furthermore, on the second axial side C2, the first actuation chamber 62 is completely axially delimited by a surface fixed to the shaft 6, such as the shaft's flange 66, while on the first axial side C1, the first actuation chamber 62 is (at least) partially delimited by a surface fixed to the coupling sleeve 8, such as the sleeve's shoulder 68, and on which the corresponding axial force E3 is exerted. As for the second actuation chamber 64, it is axially delimited on the first axial side C1 by a surface fixed to the shaft 6, such as the flange 66, and on the second axial side C2 by a surface fixed to the coupling sleeve 8, such as the sleeve's flange 69, and on which the corresponding axial force E4 is exerted. Of course, other configurations of the surfaces delimiting the actuation chambers 62 and 64 are possible.

[0090] The second shaft 6 comprises, for example, one or more third drain holes 70 connecting the first actuation chamber 62 with the exterior of the shaft, and one or more fourth drain holes 71 connecting the second actuation chamber 64 with the exterior of the shaft, as will appear more clearly below.

[0091] Furthermore, the fluid supply device 12 advantageously includes a first supply channel 72 and a second supply channel 74 formed in the tube 10, and a device 76 ( Figure 1 ). It will therefore be understood that the apparatus 76 comprises a source capable of delivering fluid F under pressure and means for controlling the supply of fluid F to either of the supply channels 72 and 74, such as one or more valves.

[0092] The first and second supply channels 72 and 74 comprise, for example, respective inlets 80 and 82 defined in an end portion 84 of the tube 10 , located outside the second axis 6 on the second side C2 , and connected to the device 76 .

[0093] For example, the first supply passage 72 includes a first outlet 86 , a second outlet 88 , and a third outlet 90 .

[0094] The first outlet 86 and the second outlet 88 open into an intermediate lubrication chamber 92 defined between the sleeve 8 and the tube 10 .

[0095] The sleeve 8 includes a first intermediate bore 94 that places the intermediate lubrication chamber 92 in fluid communication with the first lubrication chamber 39, at least in the coupled position. The first intermediate bore 94 is formed, for example, through the spline 38. Furthermore, the sleeve 8 includes a second intermediate bore 96 that places the intermediate lubrication chamber 92 in fluid communication with the second lubrication chamber 52, at least in the coupled position.

[0096] The third outlet 90 opens into a first intermediate actuation chamber 98 defined between the sleeve 8 and the tube 10 and separated from the intermediate lubrication chamber 92 by, for example, a first portion 100 of the sleeve 8 with a restricted internal section shaped so as to provide a small clearance relative to the tube 10 and thus to limit the axial flow of the fluid F on either side of this portion 100 as best as possible.

[0097] The sleeve 8 comprises a third intermediate bore 102 placing the first intermediate actuation chamber 98 in fluid communication with the first actuation chamber 62 at least in the coupled position.

[0098] The first portion 100 of the sleeve 8 having a restricted internal section is arranged to provide a small clearance relative to the tube 10 independently of the axial position of the sleeve 8 (from the coupled position to the decoupled position) and thus to maintain a sealed or substantially sealed separation between the intermediate lubrication chamber 92 and the first intermediate actuation chamber 98 during all stages of use of the assembly.

[0099] In the example shown, the third intermediate hole 102 is arranged independently of the axial position of the sleeve 8 (from the connected position to the disconnected position) so that the first intermediate actuating chamber 98 is fluidically connected to the first actuating chamber 62, which allows reversible operation of the assembly 2, as will become more clear below.

[0100] For example, the second supply channel 74 comprises an outlet 104 opening into a second intermediate actuation chamber 106 defined between the sleeve 8 and the tube 10 and communicating with the second actuation chamber 64 via a fourth intermediate hole 108 formed through the sleeve 8. To this end, the fourth intermediate hole 108 is arranged, for example, on the first side C1 relative to the flange 69.

[0101] The second intermediate actuation chamber 106 is separated from the first intermediate actuation chamber 98, for example, by a second portion 110 of the sleeve 8 having a restricted internal section, which is shaped to provide a small gap relative to the tube 10 and thus to limit the axial flow of the fluid F on both sides of this portion 110 as best as possible.

[0102] The second portion 110 of the sleeve 8 having a restricted internal section is arranged to provide a small gap relative to the tube 10 independently of the axial position of the sleeve 8 (from the connected position to the disconnected position) and thus maintain a sealed or substantially sealed separation between the first intermediate actuation chamber 98 and the second intermediate actuation chamber 106 during all stages of use of the assembly.

[0103] Furthermore, in the example shown, the second drain hole 58 , the third drain hole 70 and the fourth drain hole 71 open into the interface 112 for meshing the spline 25 of the second shaft 6 with the idler pinion 26 and therefore enable lubrication of said interface 112 .

[0104] In operation, the coupling sleeve 8 is initially in the coupling position ( Figure 2 ), the device 76 supplies pressurized fluid F to the first supply channel 72, but does not supply pressurized fluid F to the second supply channel 74, thereby supplying fluid F to the lubrication chambers 39 and 52 and the first actuation chamber 62 through the outlets 86, 88 and 90, the intermediate lubrication chamber 92, the first intermediate actuation chamber 98, and the corresponding intermediate holes 94, 96, 102. As a result, on the one hand, the coupling devices 37 and 48 are lubricated, and on the other hand, a first axial force F1 is applied to the coupling sleeve 8 to keep the coupling sleeve 8 in the coupled position.

[0105] In the example shown, the fluid F is supplied to the interface 112 for meshing the second shaft 6 with the idler pinion 26 via the second drain opening 58 and the third drain opening 70 .

[0106] When it is necessary to decouple the shafts 4 and 6, the device 76 is controlled to reverse the supply to the supply channels 72 and 74, i.e., the supply to the first supply channel 72 is stopped and the supply to the second supply channel 74 is started ( Figure 3 ).

[0107] By centrifugal effect, the intermediate lubrication chamber 92 and the first intermediate actuation chamber 98 are drained through the corresponding intermediate holes 94 , 96 , 102 , while the first lubrication chamber 39 is drained through the first drain hole 44 .

[0108] The second supply channel 74 supplies the second intermediate actuation chamber 106 through the outlet 104 . From the second intermediate actuation chamber 106 , the fluid F enters the second actuation chamber 64 through the fourth intermediate orifice 108 .

[0109] The pressure of the fluid F in the chamber 64 causes a second axial force F2 to be applied to the coupling sleeve 8, so that the coupling sleeve 8 moves toward the second side C2 until it moves to the disconnected position ( Figure 4 ).

[0110] During this phase, the interface 112 for meshing the second shaft 6 with the idler pinion 26 continues to be supplied with fluid F from the second actuating chamber 64 at least through the fourth drain orifice 71 .

[0111] In some embodiments, synchronization means (not described herein) can bring the shafts 4 and 6 into alignment and into angular alignment, so as to be able to recouple the shafts 4 and 6. In this case, the device 76 is controlled to re-reverse the supply to the channels 72, 74, i.e., to stop supplying the second supply channel 74 and to start supplying the first supply channel 72 again, so that the first axial force F1 is again exerted on the coupling sleeve 8 and moves the coupling sleeve 8 into the coupled position.

[0112] Thus, it is generally seen that the first supply channel 72 is in fluid communication with the aforementioned first selection of chambers, wherein the aforementioned first selection of chambers includes the two lubrication chambers 39, 52 and the first actuation chamber 62, while the second supply channel 74 is in fluid communication with the aforementioned second selection of chambers, which in this example only includes the second actuation chamber 64.

[0113] exist Figures 2 to 4 In the first embodiment shown, as explained above, the lubrication chambers 39 and 52 are configured so that the pressure of the fluid F in said chambers results in a zero or small axial force being exerted on the coupling sleeve 8 relative to the axial force generated by the pressure of the fluid F in the first actuation chamber 62. In other words, in the formation of the first axial force F1, the contribution of the pressure of the fluid F in the first actuation chamber 62 is (obviously) dominant.

[0114] Furthermore, while the actuation chambers have been described as annular chambers, alternatively, one and / or the other of the actuation chambers 62 and 64 may be replaced by a plurality of chambers in the form of annular segments angularly distributed about the axis 14 .

[0115] Furthermore, the coupling devices 37, 48 may be of different types. These coupling devices may be dog clutches.

[0116] Alternatively, the first actuation chamber 62 may be omitted, in which case the first axial force F1 may be absent or may have a relatively moderate level, generated only by the configuration of the lubrication chambers 39 , 52 , while the second axial force F2 is still determined by the second actuation chamber 64 .

[0117] Figures 5 to 7 A second embodiment of the present invention is shown, which is generally similar to Figures 2 to 4 However, in this second embodiment the two actuating chambers 62, 64 are omitted.

[0118] In this case, the first axial force F1 and the second axial force F2 are generated by the presence or absence of the fluid F in the lubrication chambers 39 and 52 , respectively.

[0119] To this end, in a manner similar to that described above with respect to the first embodiment, the first supply channel 72 comprises, for example, an outlet 114 opening into a first intermediate lubrication chamber 116 defined between the tube 10 and the coupling sleeve 8 and communicating with the first lubrication chamber 39 via the first intermediate hole 94 .

[0120] Furthermore, the second supply channel 74 comprises, for example, an outlet 118 opening into a second intermediate lubrication chamber 120 which is also defined between the pipe 10 and the coupling sleeve 8 and which communicates with the second lubrication chamber 52 via the second intermediate bore 96 at least in the coupled position.

[0121] It is also preferred that the second intermediate lubrication chamber 120 is separated from the first intermediate lubrication chamber 116, for example by providing a limited gap 121 between the sleeve 8 and an end portion 122 of the tube 10 located on the first side C1, regardless of the axial position of the sleeve 8 (from the coupled position to the decoupled position).

[0122] Furthermore, the coupling sleeve 8 is shaped so as to maintain the seal of the first lubrication chamber 39 regardless of the axial position of the sleeve 8 (from the coupled position to the decoupled position). To this end, the structure 42 is positioned so as to be surrounded by the first shaft 4 regardless of the axial position of the sleeve 8 between the aforementioned positions. Where appropriate, the groove 46 accommodating the compressible annular seal 45 is positioned so as to be surrounded by the first shaft 4 regardless of the axial position of the sleeve 8 between the aforementioned positions, in such a way that contact is maintained between the seal 45 and the first shaft 4.

[0123] In this context, the lubrication chambers 39 and 52 are configured such that the axial forces E1 and E2 respectively exerted on the sleeve 8 due to the fluid pressure F inside these lubrication chambers 39 and 52 generate a resultant force directed toward the first side C1 and defining the aforementioned first axial force F1, the axial force E1 being directed toward the second side C2 and defining the aforementioned second axial force F2.

[0124] A person skilled in the art will understand that in this context the means for achieving this result again depend on the choice of the orientation of the surfaces delimiting the lubrication chambers 39 and 52, on the choice of the inner and outer diameters of the chambers, and on the choice of the surface arranged, on the first side C1 or on the second side C2, respectively, to be fixed to the sleeve 8 or to one of the shafts 4 and 6.

[0125] Thus, in operation, the coupling sleeve 8 is initially in the coupling position ( Figure 5), the device 76 supplies pressurized fluid F to the first supply channel 72 and the second supply channel 74, thereby supplying the lubrication chambers 39 and 52 with fluid F through the outlets 114 and 118, the first intermediate lubrication chamber 116 and the second intermediate lubrication chamber 120, and the corresponding intermediate holes 94 and 96. As a result, on the one hand, the coupling devices 37 and 48 are lubricated, and on the other hand, a first axial force F1 is applied to the coupling sleeve 8 to keep the coupling sleeve 8 in the coupled position.

[0126] In the example shown, the fluid F is supplied to the interface 112 for meshing the second shaft 6 with the idler pinion 26 via the second drain opening 58 .

[0127] When it is necessary to decouple the shafts 4 and 6, the command device 76 stops supplying the second supply channel 74 ( Figure 6 ).

[0128] By the centrifugal effect, the second intermediate lubrication chamber 120 is drained through the second intermediate bore 96 , while the second lubrication chamber 52 is drained through the second drain bore 58 .

[0129] The first supply channel 72 continues through the outlet 114 to supply the first intermediate lubrication chamber 116 . From the first intermediate lubrication chamber 116 , the fluid F continues through the first intermediate bore 94 to supply the first lubrication chamber 39 .

[0130] The pressure of the fluid F in the chamber 39 causes a second axial force F2 (equal to the axial force E1) to be applied to the coupling sleeve 8, thereby causing the coupling sleeve 8 to move towards the second side C2 until it moves to the disconnected position ( Figure 7 ).

[0131] During this phase, the interface 112 for meshing the second shaft 6 with the idler pinion 26 is no longer supplied with fluid F from the second lubrication chamber 52. In some cases, additional means (not depicted) may be provided to ensure that, in addition to or instead of the orifice 58, the interface 112 is supplied with lubricating fluid, at least in the disconnected position.

[0132] Thus, it is seen in the context of this second embodiment that the first supply channel 72 is in fluid communication with the aforementioned first selection of chambers, which includes both lubrication chambers 39 , 52 , while the second supply channel 74 is in fluid communication with the aforementioned second selection of chambers, which in this example includes only the first lubrication chamber 39 .

[0133] Generally, in the context of the embodiment described, all axial forces applied to the coupling sleeve 8 are generated by the pressure of the fluid F in the associated chamber. Consequently, the assembly 2 for realizing a separable coupling is constructed without preload.

[0134] In such Figure 8 In the other embodiment shown, a preload spring 130 is further inserted between the stator 16 and the coupling sleeve 8 in order to exert an additional axial force F1 add on the coupling sleeve 8 towards the first axial side C1 .

[0135] The spring 130 can be arranged not to rotate, mounted to bear against the stator 16. A bearing system (not shown) capable of transmitting axial loads can be inserted between the spring 130 and the coupling sleeve 8 so that the rotation of the sleeve along the axis 14 is not interfered with by the spring supported on the sleeve.

[0136] The additional axial force F1add is superimposed on the first axial force F1, so that the coupling sleeve 8 can be ensured to remain in the coupled position, including ensuring that the coupling sleeve 8 remains in the coupled position in the following circumstances: at low speeds, due to the low intensity of the centrifugal effect, the pressure of the fluid in the corresponding fluid chamber may be insufficient for this purpose.

Claims

1. A component (2) for realizing a detachable connection of an aircraft propulsion component (1), comprising: - a first shaft (4) and a second shaft (6) which are rotatably mounted relative to a stator (16) along an axis (14); a coupling sleeve (8) comprising first coupling means (37) arranged on a first axial side (C1) and second coupling means (48) arranged on a second axial side (C2), the coupling sleeve (8) being axially movable between a first position, in which the first and second coupling means (37, 48) are coupled to the first and second shafts (4, 6), respectively, and a second position, in which the coupling sleeve (8) is displaced relative to the first position towards the second axial side (C2), such that the first coupling means (37) is decoupled from the first shaft (4); a fluid chamber (39, 52, 62, 64) defined between the coupling sleeve (8) and at least one of the first and second shafts (4, 6); - a tube (10) fixed to the stator (16) and extending into the bore of the coupling sleeve (8); as well as a fluid supply device (12) configured to selectively supply fluid (F) to a first selected one of the fluid chambers (39, 52, 62; 39, 52) and a second selected one of the fluid chambers (64; 39) through the tube (10); Wherein, the fluid chamber is configured such that: - at least when the coupling sleeve (8) is in the first position, the pressure of the fluid (F) in the first selected chamber (39, 52, 62; 39, 52) applies to the coupling sleeve a first axial force (F1) directed towards the first axial side (C1); and - the pressure of the fluid (F) in the second selected chamber (64; 39) applies to the coupling sleeve (8) a second axial force (F2) directed towards the second axial side (C2) to bring the coupling sleeve (8) into the second position.

2. The assembly according to claim 1, wherein The fluid supply device (12) includes a first supply channel (72) in fluid communication with the first selected chamber (39, 52, 62; 39, 52), a second supply channel (74) in fluid communication with the second selected chamber (64; 39), and a device (76) for selectively supplying the fluid (F) to the first supply channel (72) and the second supply channel (74).

3. The assembly according to claim 1 or 2, wherein The first selected chambers include lubrication chambers (39, 52) of the first and second coupling devices (37, 48), and at least one first actuation chamber (62), the at least one first actuation chamber being configured such that, at least when the coupling sleeve (8) is in the first position, the first axial force (F1) is at least primarily generated by the pressure of the fluid (F) in the at least one first actuation chamber (62).

4. The assembly according to claim 3, wherein The second selection of chambers includes at least one second actuation chamber (64) and excludes the lubrication chambers (39, 52) of the first and second coupling devices (37, 48).

5. The assembly according to claim 1 or 2, wherein The first selected chambers include only one or more lubrication chambers (39) of the first coupling device (37) and one or more lubrication chambers (52) of the second coupling device (48), and the second selected chambers include only one or more lubrication chambers (39) of the first coupling device (37).

6. The assembly according to any one of claims 1 to 5, wherein The first and / or second coupling means (37, 48) form a spline or define a dog clutch connection.

7. A propulsion assembly (1) for an aircraft, comprising a receiver (32), an electric motor (24), a turbine (30), and an assembly (2) according to any one of claims 1 to 6, wherein: The first shaft (4) of the assembly is mechanically engaged with the rotor (22) of the electric motor (24), and the second shaft (6) of the assembly is mechanically engaged with the rotor (28) of the turbine (30), and wherein at least one of the electric motor (24) and the turbine (30) is configured to transmit propulsion power to the receiver (32).

8. The propulsion assembly of claim 7, comprising an idler pinion (26) mechanically engaged with the second shaft (6) and the rotor (28) of the turbine (30).

9. The propulsion assembly of claim 8, wherein: At least the first selected chamber is in fluid communication with an interface (112) for meshing the second shaft (6) with the idler pinion (26).

10. The propulsion assembly of claim 9, wherein: The second selected chamber is also in fluid communication with the interface (112).

11. A propulsion assembly according to any one of claims 7 to 10, wherein: The electric motor (24) is configured to receive propulsion power from the first shaft (4).

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